Sitting and squatting water closet and seat with cistern below

ABSTRACT

A water closet (WC) or toilet bowl usable in either in the: 1) sitting, 2) front facing squatting, or 3) rear facing squatting postures. The WC consists of an elongated receptacle ( 10 ) similar in ratio of length to width to an eastern squatting-type WC, with shrouds ( 11 ) at each end to contain urine spray and footrests on each side, at a slightly lower level than the receptacle, but at such a height above the floor that mounting the footrests is not uncomfortably precarious. The volume below the receptacle and footrests is used for a cistern, fed from a normal pressurised water supply, so that the flush water source is near the siphon jet entrance at the front part of the S-bend. A hinged seat, of suitable thickness/height so that when folded down and resting on the receptacle, forms a suitably high ring-shaped sitting surface.

FIELD OF THE INVENTION

This invention relates to water closets (WC), also known as toilet bowls.

BACKGROUND OF THE INVENTION

The modern western WC requires the user to sit on it during use. However, in many other societies, for example Asian countries, squatting while defecating or urinating is a common practice. Studies have shown that adopting the squatting posture during elimination of bodily wastes has health benefits. However, persons with disorders of the knees or the back, for example in elderly persons, may be unable to adopt a squatting posture. For such persons, they are constrained to using the sitting-type western WC. Therefore, the ideal WC is one that can cater to both sitting and squatting.

A similar invention is disclosed in U.S. Pat. No. 4,012,797. However, its construction consists of a large platform which appears more part of the bathroom than part of the WC. Thus its installation will be more difficult compared to that of the western WC. The same can be said of the Asian squatting WC (except raised pedestal-type Thai designs), which either requires hacking into the floor or building up a raised floor to accommodate the depth of the bowl. Additionally, in spite of its having the potential for using the volume below the toilet bowl as a cistern, no such claim was made. In a conventional WC, water remains in its lower part in the S-bend, forming a water seal to prevent foul odours from the sewer pipe from entering the bathroom. In the said US patent, however, the invention is intended for installation on a vehicle (aeroplane, train, etc.), and no claims were made with respect to the design of the S-bend and water level in relation to the user.

In either the sitting or squatting WC, splashing of the water from the lower part of the bowl during defecation is a nuisance. A possible method to reduce splashing is by having the water level to be at an appropriate level below the anus of the user, usually not too low. This is achieved by designing the weir part of the S-bend at a high level. However, to flush such a toilet bowl, the S-bend has to be filled sufficiently quickly with a large amount of water in order to initate siphon action in the S-bend, which then sucks out waste in the bowl. In recent years, pressure to conserve water has forced designers to reduce the previously large amount of water required to initiate siphon action, by using ever larger flush valves in the cistern or using pressurised flushing systems. Working in contradiction to this desire to conserve water is the need to have a S-bend with a large diameter to reduce the risk of blockage: a large diameter S-bend requires more water to initiate siphon action.

Logical analysis of the circumstances will lead to the conclusion that placement of the source of flush water should be adjacent to siphon jet at the front of the S-bend, with a flush valve between the water source and the jet. This eliminates the convoluted path that the flush water has to take before passing through the siphon jet. However, the space immediately in front of the S-bend is confined in its upper boundary by the WC pan. Hence it cannot store flush water at a high elevational head. This then leads to the conclusion that a pressurised cistern is required, which derives its pressure from the static supply pressure of the water supply. The typical static supply pressure is at least 1.3 bars, which translates into 13 metres of elevational head, a figure much higher than any high-mounted gravity cistern can offer. Thus the combination of 1) the flush valve being adjacent to the siphon jet, 2) the close proximity of the water source to the jet and 3) the high pressure of the water source leads to extremely rapid initiation of siphon action, which reduces the water used in flushing.

In other bowls, another method to eliminate splashing is to design the WC such that stools land not over water, but on a substantially dry part of the WC pan. In such designs, two disadvantages arise: 1) the odour of the stools are not isolated by their being submerged in water; and 2) the stools leave stains on the surface of the bowl, which flushing may not successfully remove. Conversely, this feature is useful if the stools need to be examined or collected for medical diagnostic purposes.

Also currently available (from the Indian sub-continent) are WCs which appear like a normal western sitting WC with wing-like foot rests extending from each side of its rim. The level of the foot rests is approximately at sitting height. Hence, climbing onto the foot rests is an uncomfortable and precarious act. In contrast, are the raised pedestal-type squatting WCs (from Thailand) whose foot rests are at a lower level and are hence easier to mount. However, such WCs cannot be used in the sitting posture because the height of the WC pan is too low. In both types, any shifting of the feet while taking up the squatting posture has the risk of slipping and falling off the foot rests onto the floor or into the toilet bowl. On the other end of the scale is the regular Asian WC, whose foot placement is at floor level. This is also not ideal as a person walking about in the toilet, especially in poor lighting, risks slipping and falling into the WC pan.

It is with these backgrounds that the present invention is conceived.

Objects of the Invention

The object of the invention is to provide a WC that overcomes the imperfections of existing sitting, squatting and combination sitting and squatting WCs. Hence the invention shall:

1. be usable with either a sitting or a squatting posture;

2. when used in the squatting posture, be usable facing either end of the WC;

3. (as a collorary to object 2 above) allow either the stools to drop onto the substantially dry part of the interior of the WC pan (for ease of stool observation and/or stool sample collection or in the case of diarrhoea, to avoid splashing) or allow the stools to drop into the water present in the wet part of the WC pan (to quickly seal off foul odours from the stools);

4. have hoods at each end to catch urine spray;

5. have foot rests that are elevated above floor level (to minimise the risk of slipping into the WC pan while walking about in the toilet) but at a resonable height (so that mounting the WC for squatting is safe and comfortable);

6. have a raised rim demarcating the foot rests and the WC pan to further reduce the risk of slipping into the WC pan during use;

7. have a water level not too far below the anus when used in either the sitting or squatting posture so that splashing is minimised or even eliminated;

8. be convenient to install with no need to hack a hole in the toilet floor or build up a raised floor to accept the WC;

9. utilise the volume below the WC pan in front of the S-bend for a cistern to contain the flush water so that the water need not take a long and convoluted path to pass though the siphon jet and enter the S-bend;

10. utilise the static pressure of the water supply to overcome the lack of elevational head of the cistern location described in object 9;

11. require a relatively small amount of water for flushing, due to the combination of objects 9 and 10.

DESCRIPTION OF THE DRAWINGS

The accompanying drawings which are incorporated into and constitute a part of the description of the invention illustrate an embodiment of the invention and serve to explain the principles of the invention. It is to be understood, however, that the drawings are designed for the purposes of illustration only, and not as a definition of the limits of the invention for which reference should be made to the claims which will be submitted separately at a later date.

FIG. 1 is the overall view of the preferred embodiment of the present invention, with one of its foot rests show partially cut-away.

FIG. 2 is a sectional side view of the above embodiment, with a user in the preferred squatting posture, facing the front end of the WC with the cistern shown unsectioned.

FIG. 3 is a detailed section view of the rim flush outlet region.

FIG. 4 is a sectional side view with a user in the alternative squatting posture, facing the rear end of the WC.

FIG. 5 is a view showing the seat in the lowered position with a user in the usual sitting posture facing the front end of the WC.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

Referring to FIG. 1, the WC of the present invention consists of an elongated receptacle 10 similar in ratio of length to width to an eastern squatting-type WC. Additionally, there are shrouds 11 and 12 on each end of the receptacle 10 to contain urine spray. With the said shrouds being installed at boths ends means that the WC can be used when squatting facing either end. Along each side of the receptacle 10, a little lower than its side rim 13, is a foot rest 14. The said foot rest are shaped like the outline of two footprints placed facing opposite directions heel-to-heel, for ergonomics as well as to indicate to users their intended use. The level of the said foot rests is such that when a user squats on them, the side rim 13 of the receptacle 10 is of sufficient height to prevent the feet from slipping into the receptacle 10. One of the foot rests 14 is shown partially cut-away to reveal a cistern 15. In order to allow access to the cistern 15 for installation, maintenance or other similar purposes, in the present embodiment, the foot rests 14 are designed as independent units separate from the central unit 9 containing receptacle 10. During installation of the complete WC, the central unit 9 is substantially permanently installed onto the floor of the bathroom, with its trap outlet 8 properly sealed. After that, the cistern 15 and various mechanisms related to flushing are installed and/or adjusted. Finally, the two foot rests are installed, in a removable manner, to provide access in future. However, it is to be understood that other embodiments employing other means of providing access to cistern 15 remain within the scope of the present invention.

Referring to FIG. 2, in the lower part of the receptacle 10 at the rear end is the S-bend 16, which remains filled with water after flushing, thus forming a water seal against foul odours from the sewer. The weir 17 of the S-bend is of such a level that the water level 18 after flushing is not too much lower than the user's anus when he is squatting on the toilet bowl. This reduces splashing during defecation. FIG. 2 also shows the user adopting the preferred squatting posture facing the front end of the WC. This posture is familiar to South East Asian squat toilet users. It is apparent that the stools will drop into water, which will quickly seal off fouls odours from them.

Referring also to FIG. 2, the cistern 15 for storing flush water is located below the foot rest 14 and the receptacle 10. The flow of flush water from the cistern 15 is controlled by flush valve 22, immediately adjacent to the siphon jet entrance 20, hence improving the speed of initiating siphon action, thus conserving water. It is apparent that the placement of the cistern 15 in such a low position means that the elevational head of the water in the cistern will be insufficient for flushing. To overcome this, the cistern 15 must be fed from a pressurised water supply, which is almost universally available in any modern home. The pressurised water supply will fill the cistern 15, trapping air in its upper part to such a point where the pressure in the cistern is equal to the static pressure of the supply. During flushing, the flush valve 22 is opened and the pressurised water in the cistern 15 is discharged quickly through the siphon jet entrance 20 into the S-bend 16, thus quickly initating the siphon action. The volume of water discharged during each flush is controlled by proper design of the flush valve. While the present embodiment shows the cistern as a separate unit, it is to be understood that the alternative design of having the cistern integral with the WC remain within the scope of the present invention.

Also shown in FIG. 2 are two channels 23 and 24 for directing water to the front rim 25 and back rim 26 of receptacle 10 respectively. Several methods of supplying and controlling the flow of water through these channels 23 and 24 are possible. For example, they can be supplied with water separately from the cistern 15. During flushing, water though them may be turned on first to clean the interior of receptacle 10, after a short delay which the flush valve 22 opens to initiate siphon action, subsequently which they remain on for a short while after the siphon action breaks in order to refill the S-bend. Another possibility is to perform a water saving partial flush by turning on the water in the flush channels 23 and 24 only without opening flush valve 22. Yet another possibility is that the said channels are supplied with water via the same flush valve 22.

FIG. 3 shows the option using a water nozzle 27 over the outlet of flush channel 23. Referring back to FIG. 2, this option may also be employed at the outlet of flush channel 24. This option eliminates the need for a water channel and water outlet holes in the front rim 25, side rims 13 and back rim 26, which requires an additional process during the manufacture of the WC and is a location of dirt accumulation. The nozzle is made of a material that can be formed accurately during manufacture, for example, injection moulded plastic, so that the water spray can be accurately formed to cover the entire inner surface of receptacle 10 without missing any area or to have the desired flow pattern. For example, a relatively larger diameter water stream can be made to flow along the underside of the rims 25 and 13 so that sufficient water is available to arrive at the centre part of receptacle 10. A relatively thinner film of water flow can be made to flow over other parts of the receptacle. A larger water stream can also be made to flow along the lowermost part of receptacle 10 to hydraulically push stools (if any) into the S-bend. Additionally, the nozzle 27 as shown is removable for detailed cleaning. It may also be desirable to make the nozzle with a material that floats so that if it accidentally drops into the WC, it can be recovered easily.

FIG. 4 shows a user adopting the alternative squatting posture facing the rear end of the WC. This posture is familiar to East Asian squat toilet users. It is apparent from this figure that the stools will land on the substantially dry part 28 of receptacle 10. Although this method of use does not seal off foul odours from the stools, it is useful when stool observation or collection is desired. Additionally, in the case of diarrhoea, this method of use allows the liquid stools to land on a concave and sloping surface very close to the anus, thus reducing or even eliminating splashing. The reduction of splashing can also be assisted by turning on the water flow in the channel 23, so that a film of fast flowing water carries the stools away as they land.

FIG. 5 shows the toilet seat 29 in the lowered position. Due to the presence of shrouds 11 and 12, the seat height is generally above the level of the said shrouds and hence is at a comfortable sitting height. The seat may have suitable numbers of vertical webs 30 on each side which fit on top of side rim 13 to support the weight of the seated user.

While only the preferred embodiment of the present invention has been described and illustrated, it is to be understood that many changes, modifications and variations could be made to the toilet bowl of the present invention without departing from the scope or spirit of the invention. 

1. A water closet comprising: a substantially elongated toilet bowl, the toilet bowl comprising a pan section disposed at a first end and a siphoning section disposed at the opposing end for siphoning waste out of the toilet bowl; and a pressurised cistern for storing flush water for releasing into the siphoning section; wherein the pressurised cistern is disposed in a space substantially below the pan section and adjacent to the siphoning section.
 2. The water closet as claimed in claim 1, further comprising a toilet seat pivotally coupled to the toilet bowl and configured to rest above the toilet bowl in a lowered position.
 3. The water closet as claimed in claim 1, further comprising a foot rest disposed on either side of the toilet bowl, wherein the foot rest is elevated with respect to a floor.
 4. The water closet as claimed in claim 3, wherein the foot rest is positioned lower than a side rim of the toilet bowl.
 5. The water closet as claimed in claim 3, wherein the foot rest is detachable with respect to the toilet bowl.
 6. The water closet as claimed in claim 1, wherein a weir of the siphoning section is configured for maintaining a water seal at substantially the same level as a top surface of the pan section.
 7. The water closet as claimed in claim 1, wherein the pressurised cistern is coupled to a pressurised water supply.
 8. The water closet as claimed in claim 1, wherein the pressurised cistern comprises a flush valve disposed between the cistern and the siphoning section for controlling a flow of flush water.
 9. The water closet as claimed in claim 1, wherein the toilet bowl further comprises a channel for directing cleaning water to an interior surface of the toilet bowl.
 10. The water closet as claimed in claim 10, wherein the cleaning water is supplied from the cistern.
 11. The water closet as claimed in claim 11, wherein the cleaning water is supplied simultaneously with the flush water.
 12. The water closet as claimed in claim 11, wherein the cleaning water is supplied separately from the flush water.
 13. The water closet as claimed in claim 10, wherein the channel comprises a nozzle disposed at an outlet of the channel.
 14. The water closet as claimed in claim 14, wherein the nozzle is detachable from the outlet of the channel.
 15. The water closet as claimed in claim 14, wherein the nozzle is made of a plastic material suitable for injection moulding.
 16. A method for manufacturing a water closet, the method comprising the steps of: forming a substantially elongated toilet bowl, the toilet bowl comprising a pan section disposed at a first end and a siphoning section disposed at the opposing end for siphoning waste out of the toilet bowl; and providing a pressurised cistern for storing flush water for releasing into the siphoning section; wherein the pressurised cistern is disposed in a space substantially below the pan section and adjacent to the siphoning section.
 17. The method as claimed in claim 17, further comprising pivotally coupling a toilet seat to the toilet bowl, the toilet seat configured to rest above the toilet bowl in a lowered position.
 18. The method as claimed in claim 17, further comprising providing a foot rest on either side of the toilet bowl, wherein the foot rest is elevated with respect to a floor.
 19. The method as claimed in claim 19, wherein the foot rest is positioned lower than a side rim of the toilet bowl
 20. The method as claimed in claim 19, wherein the foot rest is detachable with respect to the toilet bowl.
 21. The method as claimed in claim 17, further comprising configuring a weir of the siphoning section for maintaining a water seal at substantially the same level as a top surface of the pan section.
 22. The method as claimed in claim 17, further comprising providing a flush valve between the cistern and the siphoning section for controlling a flow of flush water.
 23. The method as claimed in claim 17, further comprising providing a channel for directing cleaning water to an interior surface of the toilet bowl.
 24. The method as claimed in claim 24, further comprising providing a nozzle at an outlet of the channel.
 25. The method as claimed in claim 25, wherein the nozzle is detachable from the outlet of the at least one channel. 